The objective of the proposed study is to participate as a cooperative member of the Clinical Oncology Group performing clinical cooperative studies of solid tumors utilizing chemotherapy, surgery and radiation therapy alone or in combinations. Investigations will include a variety of Phase I, Phase II and Phase III trials in patients with advanced malignant tumors, testing new chemotherapeutic compounds alone or in various combinations. Increasing emphasis will be placed upon adjuvant therapeutic trials using chemotherapy, radiation therapy, surgical treatment and combinations thereof in potentially curable solid tumors. Adjuvant therapeutic trials presently under investigation or in the planning stage include: Preoperative Irradiation Therapy in Carcinoma of the Rectum. 5-FU as an Adjuvant in the Treatment of Colo- Rectal Cancers, Preoperative Irradiation in Patients with Carcinomas of the Intra-Oral Cavity, and Multiple Chemotherapeutic Agents as an adjuvant in the treatment of potentially curable carcinoma of the breast in patients with a poor prognosis.